Engraving machine



May 8, 1951 w. J. LARsoN ENGRAVING MACHINE 3 Sheets-Sheet l Filed Feb.26, 1946 May 8,1951 w. J. LARsN l 2,551,953

ENGRAVING MACHINE Filed Feb. 2e. 194ev 3 sheets-sheet 2 F' "98 /da i I L60 a nveuor Werne? JI La. on

W. J. LARSON ENGRAVING MACHINE May 8, 1951 3 Sheets-Sheet 5 Filed Feb.26, 1946 Patented May 8, 195

UNITED STATES PATENT OFFICE ENGRAVIN G MACHINE Werner J. Larson, WestHartford, Conn.

Application February 26, 1946, Serial No. 650,158

l 18` Claims. This invention relates particularly to an engravingmachine of the pantograph type, particularly adapted for the marking oftools, machine parts and the like. In using the machine a master isprovided carrying the words, numbers and symbols to be engraved. on thework piece, and the master is traced by a movable stylus. By means ofpantograph linkage the pattern of the masterv is engraved on the workpiece on a reduced scale by means of a suitable engraving tool.

The principal object of the invention is to provide for a machine of theclass described, irnproved means for adjusting the pantograph linkage tovary the ratio of size reduction from the master to the work piece.

A specific object of the invention is to provide means for adjusting theeffective length of one` link in association with means forcorrespondingly adjusting the effective length of another link.

Another specic object of the. invention is to provide graduations inassociation with one link for indicating the adjustments in effectivelength that are necessary for various ratios of reduction, together withmeans dependent on the effective length of the rst link for determiningthe extent of corresponding adjustment of another link.

Still other specific objects of the invention will be apparent from thefollowing specification and claims.

In the drawings I have shown in detail a preferred embodiment of theinvention, but it will be understood that various changes may be madefrom the construction shown, and that the drawings are not to beconstrued as defining or limiting the scope of the invention, the claimsforming a part of this specification being relied upon for that purpose.

Of the drawings,

Fig. 1 is a perspective View of a machine ernbodying the invention.

Fig. 2 is a plan view of the portions of the machine to which theinvention more particularly relates.

Fig. 3 is a horizontal sectional view of the portion of the machineshown in Fig. 2, this view being taken along the line 3-3 of Fig. 4.

Fig. 4 is a front view of the parts shown in Figs. 2 and 3.

Fig. 5 is a vertical sectional view taken along the line 5-5 of Fig. 4.

Fig. 6 is a fragmentary vertical sectional view taken along the line 6-6of Fig; 5.

lll)

Fig. 7 is an enlarged fragmentary vertical sectional view taken alongthe line 'I--l of Fig. 5.

' Fig. 8 is an enlarged fragmentary vertical secr tional view takenalong the line 8-8 of Fig. 5.

Fig. 9 is a view similar to Fig. 8 but showing the parts in differentrelative positions.

Figs. 10 and 11 are views. similar to Fig. 2 but showing the parts indifferent relative positions.

Fig. 12 is a diagrammatic view showing the relative movements of thelinkage during engraving, it being assumed that the parts are adjustedto the relative positions shown in Fig. 10..

The main frame of the machine may be of any usual or preferred form anda main frame. of conventional construction is illustrated. The mainframe comprises two end members Ill and I2 which are connected byhorizontal rods I4, Ill. Supported on the rods I4, I4 and adjustabletherealong is a support I6 having a platform I8 which carries thepattern or master which is to be traced in the engraving operation. Asshown, the platform I8 is provided with grooved members 20, 20 adaptedto position and hold removable elements 22, 22 having letters or numbersformed as grooves therein. These letter members 22, 22 constitute themaster and they are adapted to be traced by a stylus to be described.

The rods I4, I4 also carry a support 24 which is adjustable therealongand which is adapted to support a work piece such as 26 to be engraved.The support 24 carries suitable means for holding the work piece, andthis may be a magnetic chuck, as indicated at 28, together with aspacing block 29. In the operation of the machine a stylus Si! ismanually moved to follow or trace the master 22, 22, and by means ofpantograph linkage, to which the invention more particularly relates,the stylus causes an engraving tool 32 to reproduce the pattern of themaster on the work piece 26, such reproduction being on a reduced scale.

For supporting the pantograph linkage the end member I2 of the mainframe has an upstanding pltiOn 34 Carrying a bracket 36 to which thepantograph linkage is pivoted. The pantograph linkage comprises two mainlinks connected with each other at a movable main pivotal axis and twoauxiliary links connected with each other at a movable auxiliary pivotalaxis, the said auxiliary links being connected with the main links atsecondary pivotal axes. In accordance with the invention, the main linksare so formed that their effective lengths can be changed and each ofthem preferably comprises a main link member and a link extension, andsaid member and said extension being relatively movable longitudinally.

Referring particularly to Figs. 2 and 3, one main link member is shownat 38 and the corresponding link extension is shown at 46. These membershave tongue and groove engagement and the member 38 can be movedlongitudinally with respect to the extension 4U. The members can belocked in their adjusted positions by means of a nut 42 and screw 44.The extension 40 is pivotally connected with the bracket 36 for movementabout a vertical fixed or stationary axis at 46. The extension 4l] isprovided with horizontally projecting ears 48, 48 which are spaced apartso that the link member 38 canmove between them.

The other main link member is shown at 56, this being pivotallyconnected with the member 38 for relatively pivotal movement about avertical axis at 52, which axis will be designated as the main axis.The'axis 52 is so positioned that movement of the member 38 with respectto the extension 40 causes the said axis to move in a plane extendingthrough the stationary axis 46. Associated with the link member is anextension 54 which is longitudinally adjustable relatively thereto, thesaid link member and extension having tongue and groove engagement. Theparts can be locked in their adjusted positions by means of a nut 56engaging a screw 58. The extension 54 carries the said stylus 30, thestylus being vertically movable with respect to the extension so as toenable it to be engaged with or removed from the master 22, 22. The axisof the stylus 30 is so positioned on the extension 54 that when the saidextension is moved longitudinally with respect to the link member 50 thesaid axis moves in a plane through the movable main axis 52.

The auxiliary pantograph links are shown at 60 and 62, these beingpivotally connected with each other at a movable pivotal axis 64, whichaxis will be designated as the auxiliary axis. The auxiliary links 60and 62 are connected respectively with the main link members 38 and 5Uat axes 66 and 68, which axes will .be designated as the secondary axes.The axes 52, 68, 66 and 64 are so spaced as to be positioned at thecorners of a rectangle when the links are in the predetermined relativepositions shown in Figs. 2 and 3.

While the invention is not necessarily so limited, the said axes arepreferably so spaced that they are at the corners of a square when inthe said predetermined positions. It will be observed that the axis 66is in the same vertical plane as the axes 52 and 46 and that the axis 68is in the same vertical plane as the axes 52 and 30.

The engraving tool 32 is carried by the auxiliary links 60 and 62 at thesaid movable auxiliary pivotal axis 64. This engraving tool may be ofany usual or suitable type, but without intending to in any Way limitthe invention, I have illustrated an engraving tool adapted for electricetching. This comprisesa pointed rod 10 which extends through aninsulating bushing 'I2 and which is connected at its upper end with anelec.- tric conductor '14.V The bushing 'l2 is vertically adjustable andis held in its adjusted position by 'a set screw '15. A spring 16 biasesthe rod 10 to an elevated position and during engraving the rod ispressed downward manually so as to engage the work piece 26. It will beunderstood that the conductor 14 is connected with a suitable source ofelectrical energy, which source is grounded to the main frame oi themachine. When Jtherod is in engagement with the work piece the surfaceof the said Work piece at the point of the rod is heated suciently tomake a mark thereon as the rod is moved. The manner of operation of theelectric engraving tool is well understood and further description isunnecessary.

In order to change the ratio of reduction from the master 22, 22 to thework piece 26, the eiective lengths of two of the pantograph links mustbe changed and the length changes must be properly correlated. Inaccordance with the invention, one of the links has means relativelymovable in accordance with the changes in length thereof and serving asa guide for determining the amounts ofnecessary changes in length of theother of the said links. The said movable means on one link preferablyhas a contour line thereon, and the other link has a setting memberwhich can be brought into register with the said contour line. When thesetting member is in register with the contour line, the said other linkhas been changed in length in accordance with they change in length ofthe rst mentioned link.

In the preferred construction as shown, the

5- said ratio of reduction is determined by the adjustment of theextension 54 with respect to the member 50 and by the adjustment of themember 38 with respect to the extension 40. These adjustments are madewith the several links in predetermined primary positions. While theinvention is not necessarily so limited, the said predetermined primarypositions are preferably the said predetermined positions which areshown in Figs. 2, 3, 10 and 11. In order that that the extension 54 maybe readily adjusted for any desired reduction ratio, the said extension54 is provided with a control member or plate 18 having graduationsmarked thereon, as indicated at 80. The link member 50 carries a pointer82 which overlies the plate 18 to cooperate with the graduationsthereon. The machine, as illustrated, is particularly intended for usewith letter elements 22, 22 having letters which are 1/2 inch in height.The graduations 80 are such as to indicate the actual height of theletters or numbers to be reproduced on the work piece 26. For instance,as shown in Fig. 2, the adjustment is such as to produce letters on thework piece having a height of .090 inch, but inasmuch as the height ofthe letters on the master is 1/2 inch, the ratio of reproduction istwice the amount indicated by the marking, that is .180.

The aforesaid ratio of reduction is the same as the ratio between thedistance a from the main movable axis 52 to the adjacent secondary axis68 and the distance bfrom the said main axis 52 to the axis of thestylus 30.

It will be seen that the effective length of one main link (comprisingthe members 50 and 54) is adjusted to eiect the desired ratio ofreduction in the manner that has been described. It is necessary to alsosimilarly adjust the effective length of the other main link (comprisingthe members 38 and- 46) and this is done by adjusting the link member 38longitudinally of the link extension 40. In order that the last saidadjustment may be made conveniently, the said extension 40 is providedwith a setting member which is brought into direct juxtaposition withthe control member or plate 18 after the extension 54 with the saidplate 'I8 thereon has been properly adjusted to the desired ratio. Asshown, the plate 18 is provided with a contour line 84 thereon and theextension 40 is provided with a setting member 86 Which is adapted toregister vertically with the said contour line 84. 'Preferably but notnecessarily, the plate T8 constitutes an abutment member and its edge isshaped to conform to the contour line .84 and the setting member 86 isin the form of a stop adapted to abut directly against the contourededge of the plate. After the member 54 with the plate 18 thereon hasbeen adjusted to the desired reduction ratio, it is merely necessary tothen adjust the link member 38 on thel extension 40 so that the settingmember or stop 86 engages the contour 84. The shape of the contour issuch that, when the stop is in engagement therewith, the effectivelength of the main link comprising the members 38 and 4 '0 is correctfor the desired ratio of reduction. Thus the contour line' or edge 84 onthe link comprising the members 50 and 54 serves as a guide forchanging' the effective length of the link comprising the members 3B end40. The said correct ratio is the ratio betwen the distance c from thefixed or stationary axis 46 to the adjacent auxiliary axis 66 and thedistance d from the said fixed or stationary axis 46 to the main movableaxis 52. In other words, the construction which has been described makesit possible for the user of the machine to conveniently and quickly makethe necessary adjustments so that the ratio of c to d is the same as theratio of a. to b, this ratio being the reduction ratio of the machine.

Preferably, the stop 86 is so mounted that it can be maintained out ofits contacting position at all times except when actually needed fordetermining the proper adjustment. As shown more clearly in Figs. 6 to9, the extension 40 carries a horizontal rod 88 on which is a rotatablebushing 90 held in place by a screw 92 and a washer 94. The stop 86 isformed as an integral extension on the bushing 90. The bushing B0 isprovided with an arcuate notch 96 as shown in Fig. '7, and the extension40 carries a pin 98 which projects into the notch to limit the extent ofrotation of the bushing. The bushing carries a handle |00 by means ofwhich it may be turned. Fig. 8 shows the stop 86 in its verticalposition wherein it is adapted to engage with the contour 84 at the edgeof the plate T8. By means of the handle |00, the parts can be adjustedto the relative positions shown in Fig. 9 wherein the stop 86 is abovethe plate 1B and free from engagement therewith.

It has already been stated that the adjustments of the eiiective lengthsof the main links are made with the several links in their primarypositions, which are preferably the positions shown in Figs. 2, 4, l0and 11. provided for releasably holding the links in their said primarypositions, and as shown, this means comprises a resilient member |02carried by one of the links as for instance by the auxiliary link 60.The member |02 extends across the space between the links and is adaptedto engage the opposite link, as for instance the main link member 50.The pivot members for the pivotal connections at 52 and 68 are providedwith heads |04 and |06 and the member |02 is of such size that, whenmanually depressed, it can iit between the two heads |04 and |06 to holdall of the links in their primary positions. The resiliency of themember |02 is such that itl normally lies above the level of the heads|04 and |06, as shown in Fig. 5. Thus, the links are normally free tomove without any restriction by the said member |02 but can be locked intheir primary positions when the member |02 is manually depressed.

Figs. 10 and 11 are similar to Fig. 2, except A suitable means ispreferably i that the parts are in different positions of adjustment. InFig. 10 the adjustment isl such as to produce letters .125" in height,this representing a reduction ratio of .25.` The distance a. between theaxes 52l and 68 remains the same, but the distance b' which corresponds.to b in Fig. 2 is reduced so that the ratio of a to b is .25. Bybringing the stop 86 into engagement with the contour 84, the distancesc' and d which correspond to c and d in Fig. 2 have been changed so thatthe ratio of c' to d is .25.

In Fig. 11 the adjustment is such as to produce letters .250" in height,this representing a reduction ratio of .5. The distance a. remains thesame but the distance b" which corresponds to b and b' in Figs. 2 and 10is reduced so that the ratio of a. to b" is .5. By bringing the stop 86into engagement with the contour 84, the distances c" and d" whichcorrespond to the distances c, c' and d, d in Figs. 2 and l0 have beenchanged so that the ratio of c" to d`is .5.

Fig'. l2 is a diagrammatic view showing the relative movements of theparts, the adjustment being the same as in Fig. 10. This viewillustrates the positions of the links and of the engraving tool forvarious positions of the stylus in tracing a word on the pattern.

What I claim is:

1. In an engraving machine comprising pantograph links which include twopivotally connected main links, the combination of means for changingthe effective length of one main link, means for changing the eiectivelength of the other main link, a setting member on one of the said mainlinks relatively movable in accordance with changes in the effectivelength of the said link, and a control member on the other of the saidmain links relatively movable in accordance with changes in theeffective length of the said link, the said setting member on the rstsaid link being movable into direct juxtaposition with the controlmember on the second said main link and being so movable to differentextents according to diierent relative positions of the control memberand the said control member by reason of the said different extents ofmovement of the setting member serving to determine the correct changein the effective length of the first said main link corresponding toeach change in the effective length of the second said main link.

2. In an engraving machine comprising pantograph links which include twopivotally connected main links, the combination of means for changingthe effective length of one main link, means for changing the eiiectivelength of the other main link, a setting member on one of the said mainlinks relatively movable in accordance with changes in the effectivelength of the said link, and a control member on the other of the saidmain links relatively movable in accordance with changes in theeffective length of the said link, the said control member having acontour line thereon which is so positioned that the setting member ismovable into register therewith and which is so shaped that the settingmember upon movement into register therewith is moved to differentextents according to different relative positions of the control memberand of the contour line thereon and the said control member by reason ofthe said different extents of movement ofthe setting member serving todetermine the correct change in the eiective length of the first saidmain link corresponding to each change in the effective length of thesecond said main link.

3. In an engraving machine comprising pantograph links which include twopivotally connected main links, the combination of means for changingthe eiective length of one main link, means for changing the effectivelength of the other main link, a setting member on one of the said mainlinks relatively movable in accordance with changes in the effectivelength of the said link, and an abutment member on the other of the saidmain links relatively movable in accordance with changes in theeffective length of the said link, the said abutment member having acontour edge which is so positioned that the setting member is movableinto direct abutment therewith-and which is so shaped that the settingmember upon being moved into abutment therewith is`moved to diiTerentextents according to different relative positions of the control membei`and of the contour edge thereof and the said abutment member by reasonof the said different extents of movement of the setting member servingto determine the correct change in the eifective length of the rst saidmain link corresponding to each change in the eiective length of thesecond said main link.

- 4. In an engraving machine, the combination of two main pantographlinks connected at a movable main pivotal axis and two auxiliarypantograph links connected at a movable auxiliary pivotal axis, the saidmain and auxiliary links being connected with each other at movablesecondary pivotal axes so that when the links are in predeterminedpositions their several pivotal axes are at the corners of a rectangle,means -for connecting one main link for movement about a fixed pivotalaxis in the same plane as the main axis and the adjacent secondary axis,a stylus carried by the other main link with its axis in the same planeas the main axis and the adjacent secondary axis, the said stylus beingadapted to follow a master held in a stationary position, an engravingtool carried by the auxiliary links, means for changing the effectivelength of the second main link to change the distance between the stylusand the movable main axis, means for changing the effective length ofthe first main link to change the distance between the movable main axisand the xed axis, a control member on one of the said main linksrelatively movable in accordance with changes in the eiective length ofthe said link, and a setting member on the other of the said main linkswhich is relatively movable in accordance with changes in the effectivelength of the said link, the said setting member being movable intodirect juxtaposition ywith the control member and the said settingmember upon being so moved with the main links located in predeterminedprimary positions serving to determine the correct change in theeffective length of the setting member carrying link to correspond toeach change in the effective length of the control member carrying link.

5. An engraving machine as set forth in claim l, wherein the links arein the said predetermined primary positions when the several pivotalaxes are at the corners of a, rectangle.

6. In an engraving machine, the combination of two main pantograph linksconnected at a Amovable main pivotal axis and two auxiliary pantographlinks connected at a movable auxiliary pivotal axis, the said main andauxiliary links being connected with each other at movable secondarypivotal axes so that when the links are in predetermined positions theirseveral pivotal axes are at the corners of a rectangle, means forconnecting one main link for movement about a xed pivotal axis in thesame plane as the main axis and the adjacent secondary axis, a styluscarried by the other main link with its axis in the same plane as themain axis and the adjacent secondary axis, the said stylus being adaptedto follow a master held in a stationary position, an engraving toolcarried by the auxiliary links, means for changing the elective lengthof the second main link to change the distance between the stylus andthe movable main axis, means for changing the effective length of therst main link to change the distance between the movable main axis andthe xed axis, an abutment member on the main link carrying the styluswhich abutment member is relatively movable in accordance with changesin the effective length of the last said link and which abutment memberhas a contour edge, and a setting member on the other main link whichmember is relatively movable in accordance with changes in the effectivelength of the said link, the said setting member being movable intodirect abutment with the contour edge of the abutment member on the saidstylus carrying main link and the said setting member upon being somoved with the main links located in predetermined primary positionsserving to determine the correct change in the eiective length of thesetting member carrying link to correspond to each change in theeffective length of the abutment member carrying link.

'7. In an engraving machine, the combination of two main pantographlinks connected at a movable main pivotal axis and two auxiliarypantograph links connected at a movable auxiliary pivotal axis, the saidmain and auxiliary links being connected with each other at movablesecondary pivotal axes so that when the links are in predeterminedpositions their several pivotal axes are at the corners of a rectangle,means for connecting one main link for movement about a xed pivotal axisin the same plane as the main axis and the adjacent secondary axis, astylus carried by the other main link with its axis in the same plane asthe main axis and the adjacent secondary axis, the said stylus beingadapted to follow a master held in a stationary position, an engravingtool carried by the auxiliary links, means for changing the effectivelength of the second main link to change the distance between the stylusand the movable main axis, means for changing the effective length ofthe first main link to change the distance between the movable main axisand the fixed axis, control means carried by one main link and movablein accordance with the change in length thereof for determining theamount of change of length of the other main link which means isoperable with the links in predetermined primary positions, and meansfor releasably holding the links in their said primary positions whilethe lengths of the main links are being changed.

8. The combination in an engraving machine, of two main pantograph linkmembers connected at a movable main pivotal axis and two auxiliarypantograph links connected at a movable auxiliary pivotal axis, the saidmain link members and auxiliary links being connected with each other atmovable secondary pivotal axes so'that when the link members and linksare in predetermined positions their several pivotal axes are at thecorners of a rectangle, a link extension carrying one main link memberwhich is longitudinally movable relatively thereto, means for in astationary position, an engraving tool cari ried by the two auxiliarylinks at the auxiliary pivotal axis and adapted to engrave a work pieceheld in a stationary position, a setting member carried by the nrst saidlink extension, and a control member carried by and movable with thesecond said link extension, the said control member being positioned forcooperation with the said setting member and having a contour linethereon so shaped that when the main link members and auxiliary linksrare in predetermined primary positions and when the setting member isin register with theV said line the ratio of the distances between thefixed axis and the secondary axis adjacent the first link member andbetween the fixed axis and the main axis bears a predetermined relationto the ratio of the distances between the main axis and the secondaryaxis adjacent the second link member and between the main axis and theaxis of the stylus.

9. The combination in van engraving machine, of two main pantograph linkmembers connected at a movable main pivotal axis and two auxiliarypantograph links connected at a movable auxiliary pivotal axis, the saidmain link members and auxiliary links being connected with .each otherat movable secondary pivotal axes so that when the link members andlinks are in predetermined positions their several pivotal axes are atthe corners of `a rectangle, a link extension carrying one main linkmember which is longitudinally movable relatively thereto, means lformounting the said extension for movement about a xed pivotal axis in thesame plane as the main axis and the adjacent secondary axis, a linkextension connected with the other main link member and longitudinallymovable relatively thereto, a stylus carried by the last `said linkextension with its axis in the same plane as the main axis and theadjacent secondary axis, the said stylus being adaptedv to follow amaster held in a stationary position, an engraving tool carried by thetwo auxiliary links at the auxiliary pivotal axis and adapted to engravea work piece held in a stationary position, a setting member carried bythe first said link extension, and a control member carried by andmovable with the second said link extension, the said control memberbeing positioned for cooperation with the said setting member and havinga con-.- tour line thereon so shaped that when the mai-n link membersand auxiliary links are in predetermined primary positions and when thesetting member is in register with the said line the ratio of thedistances between the fixed axis and the secondary axis adjacent thefirst link member and between the fixed axis and the main axis is thesame as the ratio of the distances between the main axis and thesecondary axis adjacent the second link member .and between `the mainaxis and the axis of the stylus,

10. The combination in an engraving machine, of two main pantograph linkmembers connected at a movable main pivotal axis and two auxiliarypantoeraph links connected at a movable auxiuary lpivotal axis, the saidmain link members and auxiliary links being connected with each other atmovable secondary pivotal axes so that `wlfien the link members andlinks are in prede.- termined positions their several pivotal axes areat the corners of a rectangle, a link extension carrying one main linkmember which is lon.- gitudinally movable relatively thereto, means formounting the said extension for movement about a fixed pivotal axis inthe same `plane as the main axis and the adjacent secondary axis, a link.extension connected with the other main iink memand longitudinallymovable relatively thereto, a stylus carried by the last said linkextension itsraxis inthe ,same plane as the main axis and the adjacentsecondary axis, the said stylus being adapted .to follow a master heldin a sta tionary position, an engraving tool carried by the twoauxiliary links .at the auxiliary pivotal axis adapted to engrave a workpiece held in a stationary position, a setting member .carried by thelst said. link extension, a control member Carried by and movable withthe second said .link .eiieiiioib the said control member being PQSLyned for cooperation with the said setting noemer and having a contourline thereon so shaped that when the main link members and auxiliarylinks are in predetermined primary po- Sitions and when the settingmember is in regiStegI' with 'the .Said line the ratio of the distancesbetween the .xed axis and the secondary axis adjaent the ,first linkmember `and between the xeii .axis and the main axis is the same as Ytheratio of the distances between the main axis and the secondary axisadjacent the second link member and between the main axis and the axisof the Stylus, and means for releasably holding the links .in their saidprimary positions while relative ulongitudinal movement is beingeffected between the main link members and their exten- SQQS..

ll. :The combination in an engraving machine, of two main pantographlinks each comprising a link member and an .extension therefor which arerelatively movable longitudinally, the said link members being connectedat a movable main pivotal axis, two auxiliary pantograph links connestedat a movable auxiliary pivotal axis, the Said link members and auxiliarylinks being connected with each other at movable secondary pivotal axesso that when the link members and links are in predetermined positionstheir several pivotal ,axes are at the corners of a rectangle, means formounting the extension on one main link for movement about a fixedpivotal f axis in the same plane as the main axis and the adjacentsecondary axis, a stylus carried by the link extension of the other mainlink with its axis in the same plane as lthe main axis and the adjacentsecondary axis, the said stylus being adapted to follow a master held ina stationary position, an engraving tool carried by the two auxiliarylinks at the auxiliary pivotal axis and adapted to engrave a work pieceheld in a stationary position, a setting member carried by the firstSaid link extension, a control member Carried by and movable with thesecond said link extension, the said control member being positioned forcooperation with the said setting mem-V ber and having a contour linethereon so shaped that when the main link members and auxiliary linksare .in predetermined primary positions and when the setting member isin register with the said line the ratio of the distances between thefixed axis and the secondary axis adjacent the rst link member andbetween the fixed axis and the main axis is the same as the ratio' ofthe distances between the main axis and the secondary axis adjacent thesecond link member and between the main axis and the axis of the stylus,and means carried by one link and adapted to engage the link oppositethereto for releasably holding the links in their said primary positionswhile relative longitudinal movement is being effected between the mainlink members and their extensions.

12. The combination in an engraving machine, of two main pantograph linkmembers connected ata movable main pivotal axis and two auxiliarypantograph links connected at a movable auxiliary 'pivotal axis, thesaid main link members and auxiliary links being connected with eachother at movable secondary pivotal axes so that when the link membersand links are in predetermined positions their several pivotal axes areat the corners of a rectangle, a link extension carrying one main linkmember which is longitudinally movable relatively thereto, means formounting the said extension for movement about a xed pivotal axis in thesame plane as the main axis and the adjacent secondary axis, a linkextension connected with the other main link member and longitudinallymovable relatively thereto, a stylus carried by the last said linkextension with its axis in the same plane as the main axis and theadjacent secondary axis, the said stylus being adapted to follow amaster held in a stationary position, an engraving tool carried by thetwo auxiliary links at the auxiliary pivotal axis and adapted to engravea work piece held in a stationary position, a setting member carried bythe first said link extension, a control member carried by and movablewith the second said link extension, the said control member beingpositioned for cooperation with the said setting member and having acontour line thereon so shaped that when the main link members andauxiliary links are in predetermined primary positions and when thesetting member is in register with the said line the ratio of thedistances between the fixed axis and the secondary axis adjacent the rstlink member and between the xed axis and the main axis is the same asthe ratio of the distances between the main axis and the secondary axisadjacent the second link member and between the main axis and the axisof the stylus, graduations on the control member showing various ratios,and a pointer on the second link member cooperating with the saidgraduations to show the aforesaid ratios of distances for variouspositions of the control member.

13. The combination in an engraving machine, of two main pantograph linkmembers connected at a movable main pivotal axis and two auxiliarypantograph links connected at a movable auxiliary pivotal axis, the saidmain link members and auxiliary links being connected with each other atmovable secondary pivotal axes so that when the link members and linksare in predetermined positions their several pivotal axes are at thecorners of a rectangle, a link extension carrying one main link memberwhich is longitudinally movable relatively thereto, means for mountingthe said extension for movement about a xed pivotal axis in the sameplane as the main axis and the adjacent secondary axis, a link extensionconnected with the other main link member and longitudinally movablerelatively thereto, a stylus carried by the last said link extensionwith its axis in the same plane as the main axis and the adjacentsecondary axis, the

said stylus being adapted to follow a master held in a stationaryposition, an engraving tool carried by the two auxiliary links at theauxiliary pivotal axis and adapted to engrave a work piece held in astationary position, a setting member carried by the first said linkextension, a control member carried by and movable with the second saidlink extension, the said control member being positioned for cooperationwith the said setting member and having a contour line thereon so shapedthat when the main link members and auxiliary links are in predeterminedprimary positions and when the setting member is in register with thesaid line the ratio of the distances between the xed axis and thesecondary axis adjacent the first link member and between the fixed axisand the main axis is the same as the ratio of the distances between themain axis and the secondary axis adjacent the second link member andbetween the main axis and the axis of the stylus, graduations on thecontrol member showing'various ratios of size reduction between thestylus and the engraving tool which ratios are the same as the ratiosaforesaid, and a pointer on the second link member cooperating with thesaid graduations to show the ratio of size reduction for each setting.

14. The combination in an engraving machine, of two main pantograph linkmembers connected at a movable main pivotal axis and two auxiliarypantograph links connected at a movable auxiliary pivotal axis, the saidmain link members and auxiliary links being connected with each other atmovable secondary pivotal axes so that when the link members and linksare in predetermined positions their several pivotal axes are at thecorners of a rectangle, a link extension carrying one main link memberwhich is longitudinally movable relatively to the said extension, meansfor mounting the said extension for movement about a xed pivotal axis inthe same plane as the main axis and the adjacent secondary axis, a linkextension connected with the other main link member and longitudinallymovable relatively thereto, a stylus carried by the last said linkextension with its axis in the same plane as the main axis and theadjacent secondary axis, the said stylus being adapted to follow amaster held in a stationary position, an engraving tool carried by thetwo auxiliary links at the auxiliary pivotal axis and adapted to engravea work piece held in a stationary position, a stop carried by the rstsaid link extension, and an abutment member carried by and movable withthe second said link extension, the said abutment member beingpositioned to be engaged by the said stop and having its edge so shapedthat when the main link members and the auxiliary links are inpredetermined primary positions and when the stop is engaged with thesaid edge the ratio of the distances between the xed axis and thesecondary axis adjacent the rst link member and between the xed axis andthe main axis is the same as the ratio of the distances between the mainaxis and the secondary axis adjacent the second link member and betweenthe main axis and the axis of the stylus.

15. The combination in an engraving machine, of two main pantograph linkmembers connected at a movable main pivotal axis and two auxiliarypantograph links connected at a movable auxiliary pivotal axis, the saidmain link members and auxiliary links being connected with each other atmovable secondary pivotal axes so that when.

the link members and links are in predetermined ams Loss positions theirseveral pivotal axes are at the corners of a rectangle, a link extensioncarrying one main link member which vis longitudinally movablerelatively to the said extension, means for mounting the said extensionfor movement about a xed pivotal axis in the same plane as the main axisand the adjacent secondary axis, a link extension connected with theother main link member and longitudinally movable relatively thereto, astylus carried by the said last link extension with its axis in the sameplane as Athe main axis and the adjacent secondary axis, the said stylusbeing adapted to follow a master held in a stationary position, anengraving tool carried by the two auxiliary links at the auxiliarypivotal axis and adapted to engrave a work piece held in a stationaryposition, a stop carried vby the first said link extension, an abutmentmember carried by and movable with the second said 'link extension, `thesaid abutment member being positioned to be engaged by the said stop andhaving its edge so shaped that when the main link members and theauxiliary links are in predetermined primary positions and when the stopis engaged with the said edge the ratio of the distances between theiixed axis and the secondary axis adjacent the rst link member andbetween the xed axis and the main axis is the same as the ratio of thedistances between the main axis and the secondary axis adjacent thesecond link member and between the main axis and the axis of the stylus,graduations on the abutment member showing various ratios, and a pointeron the second link member cooperating with the said graduations to showthe aforesaid ratios of distances for various positions of the abutmentmember.

. 16. The combination in an engraving machine, of two main pantographlink members connected at a movable main pivotal axis and two auxiliarypantograph links connected at a movable auxiliary pivotal axis, the saidmain link members and auxiliary links being connected with each other atmovable secondary pivotal axes so that when the link members and linksare in predetermined positions their several pivotal axes are at thecorners of a rectangle, a link extension carrying one main link memberwhich is longitudinally movable relatively to the said extension, meansfor mounting the said extension for movement about a xed pivotal axis inthe same plane as the main axis and the adjacent secondary axis, a linkextension connected with the other main link member and longitudinallymovable relatively thereto, a stylus carried by the last said linkextension with its axis in the same plane as the main axis and theadjacent secondary axis, the said stylus being adapted to follow amaster held in a sta- CII tionary position, an engraving tool carried bythe two auxiliary links at the auxiliary pivotal axis and adapted toengrave a work piece held in al stationary position, a stop carried bythe first said link extension, an abutment member carriedY by andmovable with the second said link extension, the said abutment memberbeing positioned to be engaged by the said stop and having its edge soshaped that when the main link members and the auxiliary links are inpredetermined primary positions and when the stop is engaged with thesaid edge the ratio of the distances between the xed axis and thesecondary axis adjacent the first link member and between the fixed axisand the main axis is the same as the ratio of the distances between themain axis and the secondary axis adjacent the second link member and be-1,4 and means for moving the stop out of cooperative relationship withthe abutment member to avoid contact therewith during engraving.

17. An engraving machine comprising in combination, a main frame, a mainlink extension pivoted to the main frame for movement about a fixedaxis, a main link member carried by the said extension andlongitudinally adjustable with respect thereto, a second main linkmember pivota'lly' connected with the iirst main link member forrelative movement about a main axis, the said main axis being positionedto move relatively to the said link extension in a plane passing throughthe vfixed axis, a second main link extension carried by the second mainlink member and longitudinally movable with respect thereto, a stylusAcarried by the second main link extension and positioned to moverelatively to the second m-ain link member in a plane passing through'the main axis, the said stylus being adapted 'to follow a masterstationarily held on the main frame, two auxiliary links .pivotallyconnected with each other for relative movement about an auxiliary axis,the said auxiliary links being pivotally connected respectively with thesaid main link members for relative movement about secondari7 axes withone such axis in the plane extending through the fixed axis and the mainaxis and with the other such axis in the plane extending through themain axis and the axis of the stylus and the distances between theseveral movable axes being such that they are at the corners of arectangle when the main link members and auxiliary links are inpredetermined positions, an engraving tool carried by the auxiliarylinks at the said auxiliary axis and adapted to engrave a work piecestationarily held on the main frame, a setting member carried by thefirst said link extension, and -a control member carried by and movablewith the second said link extension, the said control member beingpositioned for cooperation with the said setting member and having acontour line thereon so shaped that when the main link members andauxiliary links are in predetermined primary positions vand when thesetting member is in register with the said line the ratio of thedistances between the fixed axis and the secondary axis adjacent thefirst link member and between the fixed axis and the main axis is thesame as the ratio of the distances between the main axis and thesecondary axis adjacent the second link member and between the main axisand the axis of the stylus.

18. An engraving machine comprising in combination, a main frame, a mainlink extension pivoted to the main frame for movement about a xed axis,a main link member c-arried by the said extension and `longitudinallyadjustable with respect thereto, a second main link member pivotallyconnected with the first main link member for relative movement about amain axis, the said main axis being positioned to move relatively to thesaid link extension in a plane passing through the fixed axis, a secondmain link extension carried by the second main link member andlongitudinally movable with respect thereto, a stylus carried by thesecond main link extension and positioned to move relatively to thesecond main link member in a plane passing through the main axis, thesaid stylus being adapted to follow a master stationarily held on themain frame, two auxiliary links pivotally connected with each other forrelative movement labout an auxiliary tween the main axis and the axisof the stylus, axis, the said auxiliary links being pivotally connectedrespectively with the said main link members for relative movement aboutsecondary axes with one such axis in lthe plane extending through thexed axis and the main axis and with the other such axis in the Planeextending through the main axis and the axis of the stylus and thedistances between the several movable axes being such that they are atthe corners of a rectangle when the main link members and auxiliarylinks are in predetermined positions, an engraving tool carried by theauxiliary links at the said auxiliary axis and adapted to engrave a workpiece stationarily held on the main frame, a stop carried by the firstsaid link extension, an abutment member carried by and movable with thesecond said link extension, the said abutment member being positioned tobe engaged by the said stop and having its edge so shaped that when themain link members and the auxiliary links are in predetermined primarypositions and when the stop is engaged with the said edge the ratio ofthe distances between the fixed axis and the secondary axis adjacent therst link member and between the xed axis and the main axis is the sameas the ratio of the distances between the main axis and the secondaryaxis adjacent the second link member and between the main axis and theaxis of the stylus, graduations on the abutment member showing variousratios of size reduction between the stylus and the engraving tool whichratios are the same as the ratios aforesaid, and a pointer on the secondlink member cooperating with the said graduatons to show the ratio ofsize reduction for each setting.

WERNER J. LARSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,235,668 Eaton Aug. 7, 19172,197,884 Ackerman et al. Apr. 23, 1940

